This invention relates to a projection display that displays an image by projecting a luminous flux from a laser light source having coherency to an image display device.
JP-A-2004-144936 discloses a lighting unit including a diffusion element for distributing and diffusing coherent light incident from a semiconductor laser by changing its intensity distribution to a predetermined intensity distribution, and oscillation means for oscillating this diffusion element.
JP-A-3-163333 discloses a synchronized magnetic domain observation apparatus for extracting a specific change point of a magnetic domain image that changes at a high speed, by controlling on/off of a laser beam by a high speed shutter on the basis of coherency of the laser beam.